Id double check the gear ratio that you have now, with 4.56's you should be able to go faster than 45. im guessing at least 55-60.
I know that the bigger trucks like my 2&1/2 ton which has 6.33 gears, the top speed was 45, but they also have taller tires which makes a difference.
If you do actually have 4.56's try a taller tire. They will make a difference.
Last edited by JeffL; 08/12/2012 9:14 AM.
